Next thing this guy will be giving us the "many paths up the mountain but they all lead to the peak" bullcrap. I would bet that he would not even commit to say that there is only one G-d or he would try to tell us that Allah/Marduk the Moon god are the same as YHWH.
I'm not so sure there's not more than one path to the peak (even going by what's in the Torah alone). But I do think that if that's the case, some paths MUST be shorter (and dare I say "better") than others. And then again, I'm not so sure there isn't just one path that leads to the peak.
I think he might say there's only one G-d. But that his conception of G-d would be very different than ours.
Religion is supposed to be a conservative institution, by definition. It relies on traditions, solid values, and a strong orthodox belief. Liberalized religion is just a poor model to work from, and it's very hard to go far with such a model and do what other non liberalized denominations do as well as they do. Try taking a solar powered car to the Indy 500. On a rainy day.